Fluorescent material for detecting neonicotinoid pesticides, and preparation and detection methods thereof

Abstract

The invention belongs to the technical field of pesticide detection, and relates to a fluorescent material for detecting neonicotinoid pesticides, a preparation method and a detection method. The material comprises a ZnO microsphere and a molecular imprinting template, gaps exist on the surface of the ZnO microsphere, a hollow structure exists in the center of the ZnO microsphere, the size of the ZnO microsphere is 800-1200 nm, the ZnO microsphere is composed of small particles of 4.2-7.8 nm, the molecular imprinting template wraps the ZnO microsphere, and the fluorescent material absorbs ultraviolet light of 375 nm and emits visible light of 596 nm. The material can adsorb neonicotinoid pesticides, and then the content of neonicotinoid can be judged by detecting the fluorescence signal intensity of a mixture of the adsorption material and neonicotinoid. According to the method, tedious extraction can be avoided, and the neonicotinoid pesticide does not need to be separated from an adsorption material and then detected.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticide detection, and relates to a fluorescent material for detecting neonicotinoid pesticides, and a preparation method and a detection method thereof. Background Art

[0002] As a highly effective insecticide, neonicotinoid pesticides have been widely used in agricultural production (Overview of the status and global strategy for neonicotinoids, Agric. Food Chem. 59 (2011), 2897.). With the widespread use of neonicotinoid pesticides, many problems have been exposed. For example, residual pesticides can enter the human body through water sources, food chains, etc., thus causing potential harm to human health. Therefore, the detection of neonicotinoid pesticides in the human body is of great significance.

[0003] Since neonicotinoid pesticides have a long biological half-life in the environment, neonicotinoid pesticides that enter the human body through the food chain will remain in the human body for a long time. A large number of studies have detected the presence of neonicotinoid pesticides in human urine (Quantitation of neonicotinoid metabolites in human urine using GC-MS, Journal of Chromatography B 941 (2013), 09-115.). Currently, the most commonly detected neonicotinoid pesticides are imidacloprid, thiamethoxam and acetamiprid.

[0004] Common detection methods for neonicotinoid pesticides include high performance liquid chromatography, enzyme-linked immunosorbent assay, surface enhanced Raman spectroscopy, etc. However, the content of neonicotinoid pesticides in urine is low. Existing technologies require a large number of samples for analysis and require complex pretreatment operations. For example, the most common method is to enrich and purify samples through solid phase extraction technology (Metal-organic framework MIL101(Cr)-NH2 functionalized magnetic graphene oxide for ultrasonic-assisted magnetic solid phase extraction ofneonicotinoid insecticides from fruit and water samples, Talanta 217(2020), 121120), or use a large amount of organic solvents to carry out multiple manual liquid-liquid extractions to achieve the recovery of the target. The content of the target is then detected. These pretreatment processes are complicated, time-consuming and inefficient. Summary of the invention

[0005] In order to overcome the drawbacks of the prior art, the present invention provides a fluorescent material, preparation and detection method for detecting neonicotinoid pesticides. The fluorescent material can adsorb neonicotinoid pesticides, thereby changing the luminescence intensity of the fluorescent material. Then, the content of neonicotinoid pesticides can be judged according to the strength of the fluorescent signal in the fluorescence spectrum of the detection material. This method can avoid cumbersome extraction, and there is no need to separate neonicotinoid pesticides from the adsorption material before detection. Figure 1 It is a schematic diagram of the preparation and detection process of the present invention.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] Provided is a fluorescent material for detecting neonicotinoid pesticides, comprising ZnO microspheres and molecular imprinting templates, wherein sparse hairy structures exist on the surface of the ZnO microspheres, the size of the ZnO microspheres is 800-1200 nm, and the ZnO microspheres are composed of small particles of 4.2-7.8 nm, the molecular imprinting templates wrap the ZnO microspheres, and the fluorescent material absorbs 375 nm ultraviolet light and emits 596 nm visible light.

[0008] The material can adsorb neonicotinoid pesticides very well, because there are a large number of pores on the surface of ZnO, which increases its specific surface area. In addition, the molecular imprinting template can adsorb the specified neonicotinoid pesticides. In addition, the ZnO microspheres are composed of small particles of 4.2 to 7.8 nm, so they have photoluminescence properties. The material can directly detect neonicotinoid pesticides through fluorescence spectroscopy without separating neonicotinoid pesticides and fluorescent materials by adsorbing neonicotinoid pesticides.

[0009] It is further preferred as a fluorescent material for detecting neonicotinoid pesticides.

[0010] Preferably, the molecular imprinting template is based on a neonicotinoid pesticide standard, molded with trimethylolpropane trimethacrylate and 2,2-azobisisobutyronitrile, and then repeatedly washed with acetonitrile by centrifugation to obtain an adsorption material with the ability to adsorb specified neonicotinoid pesticides.

[0011] The present invention also provides a method for preparing a fluorescent material for detecting neonicotinoid pesticides, which is characterized by comprising the following steps:

[0012] S1. Add 0.8-2.4 g of zinc acetate dihydrate (Zn(AC)2·2H2O) to 40-80 ml of anhydrous ethanol solution, heat to 60-80° C. and stir for 20-30 min. Meanwhile, dissolve 0.3-0.9 g of potassium hydroxide (KOH) in 20-40 ml of anhydrous ethanol, then add the KOH solution to the Zn(AC)2·2H2O solution, stir at 30-60° C. for 10-20 min, then add 180-360 ml of n-hexane to obtain a precipitate, centrifuge, wash, and dry to obtain a white powder.

[0013] S2. Add 0.1-0.3 g of the powder dried in step S1 to a mixed solution of 20-40 ml of benzyl alcohol and 0.5-2 g of polyethylene glycol, and stir at 60-80° C. for 3-5 hours. Then pour it into a polytetrafluoroethylene liner, seal the reaction kettle, heat it in an oven to 120-200° C., and then naturally cool it to room temperature. Then, centrifuge and wash it to obtain a material with a stable fluorescent effect.

[0014] S3, place 100-300 mg of neonicotinoid pesticide standard in a flask, add 30-100 ml of acetonitrile, 4-12 ml of deionized water and 0.1-0.5 ml of methacrylic acid and stir for 3-5 hours, then add 0.1-0.6 g of the material with stable fluorescence effect in step S2. Then add 8-30 mmol of trimethylolpropane trimethacrylate and 20-60 mg of 2,2-azobisisobutyronitrile in sequence and stir for 16-20 hours, then wash repeatedly with acetonitrile by centrifugation until the neonicotinoid pesticide standard cannot be detected, and obtain the fluorescent material for detecting neonicotinoid pesticides.

[0015] The precipitate described in step S1 is ZnO nanoparticles with a size of about 4.2 to 7.8 nm. The nanoparticles are small in size and easily agglomerated, and the crystal size grows, which easily leads to changes in the luminescence intensity and emission position. The present invention gathers small ZnO nanoparticles together by heating, and then forms them into microspheres through hydrothermal high temperature and high pressure, and the surface has a sparse hairy structure, thereby increasing its adsorption effect.

[0016] It is further preferred as a fluorescent material for detecting neonicotinoid pesticides.

[0017] Preferably, the drying condition in step S1 is 50-80° C. and the drying time is 12-18 hours.

[0018] The drying temperature in step S1 should not be too high. If the temperature is too high, the ZnO nanoparticles will be fully aggregated and have a fixed morphology, making it difficult to form ZnO microspheres with high porosity under hydrothermal conditions.

[0019] Preferably, the neonicotinoid pesticide standard in step S3 is imidacloprid.

[0020] The present invention also provides a detection method for detecting neonicotinoid pesticides, characterized in that it comprises the following steps:

[0021] Put the fluorescent material in a centrifuge tube, add methanol and vortex to remove the supernatant, then add the urine to be tested, shake for 2 to 3 minutes, and then centrifuge to obtain a white substrate, which is then dispersed in anhydrous ethanol, centrifuged again, and then dispersed in a mixed solution of isopropanol and polyvinyl pyrrolidone K-30, detect the fluorescence spectrum, and analyze the content of neonicotinoid pesticides.

[0022] It is a further optimization method for detecting neonicotinoid pesticides as fluorescent materials.

[0023] Preferably, the added amounts of the fluorescent material, methanol, urine to be tested, anhydrous ethanol, isopropanol and polyvinylpyrrolidone K-30 are 30-60 mg, 3-6 ml, 10-20 ml, 15-20 ml, 3-5 ml and 0.1-0.3 g, respectively.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The fluorescent material prepared by the present invention can adsorb neonicotinoid pesticides, and there is no need to separate the neonicotinoid pesticides from the adsorption material. The neonicotinoid content can be determined by detecting the intensity of the fluorescent signal of the mixture of the adsorption material and the neonicotinoid. This method can avoid cumbersome extraction methods and separation and purification steps.

[0026] (2) The present invention forms a stable microsphere structure by heating and hydrothermally reacting small-sized ZnO nanoparticles. The microspheres are still small-particle ZnO nanoparticles, so that they still have luminescence properties. In addition, the microsphere structure is not easy to deform, so that its luminescence properties are not easy to change spontaneously. In addition, the ZnO microspheres will form a sparse hairy structure on the surface under specific temperature, pressure and surfactant conditions, thereby increasing their adsorption.

[0027] (3) This method is very effective for the qualitative detection of neonicotinoid pesticides, and the content of neonicotinoid pesticides can be determined based on the intensity of fluorescence. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a fluorescent material, preparation and detection method for detecting neonicotinoid pesticides;

[0029] Figure 2 (a) is a transmission electron microscope photograph of the synthetic precipitate in Example 1, Figure 2(b) is the Gaussian fitting curve that counts its size;

[0030] Figure 3 is a transmission electron microscope photograph of the ZnO microspheres prepared in Example 2, Figure 3 (b) is a high-resolution transmission electron microscope photograph;

[0031] Figure 4 The fluorescence emission spectrum and excitation spectrum of the ZnO nanoparticles in Comparative Example 1 vary with time;

[0032] Figure 5 The fluorescence emission spectrum and excitation spectrum of the ZnO microspheres in Comparative Example 2 vary with time;

[0033] Figure 6 (a) is the fluorescence emission spectrum of neonicotinoid pesticides adsorbed by the fluorescent materials in Examples 1 to 6 and Comparative Example 2, Figure 6 (b) is the peak histogram of its emission spectrum. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with embodiments and comparative examples.

[0035] Example 1

[0036] This embodiment provides a fluorescent material for detecting neonicotinoid pesticides, and a preparation and detection method thereof.

[0037] The adsorption material and the preparation method thereof comprise the following steps:

[0038] S1. Add 0.8 g of zinc acetate dihydrate (Zn(AC)2·2H2O) to 40 ml of anhydrous ethanol solution, heat to 60°C and stir for 20 min. At the same time, dissolve 0.3 g of potassium hydroxide (KOH) in 20 ml of anhydrous ethanol, then add the KOH solution to the Zn(AC)2·2H2O solution, stir at 30°C for 10 min, and then add 180 ml of n-hexane to obtain a precipitate, which is centrifuged, washed, and dried to obtain a white powder. The drying temperature is 50°C and the drying time is 12 h.

[0039] S2. Add 0.1 g of the powder dried in step S1 to a mixed solution of 20 ml of benzyl alcohol and 0.5 g of polyethylene glycol, stir at 60° C. for 3 h, then pour it into a polytetrafluoroethylene liner, seal the reactor, place it in an oven, heat it to 120° C., then naturally cool it to room temperature, and then centrifuge and wash it to obtain a material with a stable fluorescent effect.

[0040] S3, 100 mg of imidacloprid standard was placed in a flask, 30 ml of acetonitrile, 4 ml of deionized water and 0.1 ml of methacrylic acid were added and stirred for 3 h, and then 0.1 g of the material with stable fluorescence effect in step S2 was added thereto. Then 8 mmol of trimethylolpropane trimethacrylate and 20 mg of 2,2-azobisisobutyronitrile were added in sequence and stirred for 16 h, and then washed repeatedly with acetonitrile by centrifugation until the imidacloprid standard could not be detected, and a fluorescent material for detecting imidacloprid was obtained.

[0041] The detection method comprises the following steps:

[0042] Take 30 mg of fluorescent material in a centrifuge tube, add 3 ml of methanol and vortex to remove the supernatant, then add 10 ml of urine to be tested, shake for 2 minutes, and then centrifuge to obtain a white substrate, which is then dispersed in 15 ml of anhydrous ethanol, centrifuged again, and then dispersed in a mixed solution of 3 ml of isopropanol and 0.1 g of polyvinyl pyrrolidone K-30, detect the fluorescence spectrum, and analyze the content of neonicotinoid pesticides.

[0043] This embodiment synthesized molecular imprinting template-wrapped ZnO microspheres, the fluorescent material absorbed 375nm ultraviolet light and emitted 596nm visible light, there were sparse hairy structures on the surface of the ZnO microspheres, the size of the ZnO microspheres was 1000nm, and the ZnO microspheres were composed of small particles of 5.9nm.

[0044] Embodiments 2 to 6

[0045] The difference between Examples 2 to 6 and Example 1 is that, in the detection method, 12 ml, 14 ml, 16 ml, 18 ml and 20 ml of urine to be tested are added respectively.

[0046] Example 7

[0047] This embodiment provides a fluorescent material for detecting neonicotinoid pesticides, and a preparation and detection method thereof.

[0048] The adsorption material and the preparation method thereof specifically comprise the following steps:

[0049] S1. Add 2.4 g of zinc acetate dihydrate (Zn(AC)2·2H2O) to 80 ml of anhydrous ethanol solution, heat to 80°C and stir for 30 min. Meanwhile, dissolve 0.9 g of potassium hydroxide (KOH) in 40 ml of anhydrous ethanol, then add the KOH solution to the Zn(AC)2·2H2O solution, stir at 60°C for 20 min, then add 360 ml of n-hexane to obtain a precipitate, centrifuge, wash and dry it to obtain a white powder. The drying temperature is 80°C and the drying time is 18 h.

[0050] S2. Add 0.3 g of the powder dried in step S1 to a mixed solution of 40 ml of benzyl alcohol and 2 g of polyethylene glycol, stir at 80° C. for 5 h, then pour it into a polytetrafluoroethylene liner, seal the reactor, heat it to 200° C. in an oven, and naturally cool it to room temperature. Centrifuge and wash it to obtain a material with a stable fluorescent effect.

[0051] S3, 300 mg of imidacloprid standard was placed in a flask, 100 ml of acetonitrile, 12 ml of deionized water and 0.5 ml of methacrylic acid were added and stirred for 5 hours, and then 0.6 g of the material with stable fluorescence effect in step S2 was added thereto. Then 30 mmol of trimethylolpropane trimethacrylate and 60 mg of 2,2-azobisisobutyronitrile were added in sequence and stirred for 20 hours, and then washed repeatedly with acetonitrile by centrifugation until no neonicotinoid pesticide standard was detected, and the fluorescent material for imidacloprid was obtained.

[0052] Detection method:

[0053] Take 60 mg of fluorescent material in a centrifuge tube, add 6 ml of methanol and vortex to remove the supernatant, then add 20 ml of urine to be tested, shake for 3 minutes, and then centrifuge to obtain a white substrate, which is then dispersed in 20 ml of anhydrous ethanol, centrifuged again, and then dispersed in a mixed solution of 5 ml of isopropanol and 0.3 g of polyvinylpyrrolidone K-30, detect the fluorescence spectrum, and analyze the content of neonicotinoid pesticides.

[0054] This embodiment synthesized molecular imprinting template-wrapped ZnO microspheres, the fluorescent material absorbed 375nm ultraviolet light and emitted 596nm visible light, there were sparse hairy structures on the surface of the ZnO microspheres, the size of the ZnO microspheres was 800nm, and the ZnO microspheres were composed of small particles of 4.2nm.

[0055] Example 8

[0056] This embodiment provides a fluorescent material for detecting neonicotinoid pesticides, and a preparation and detection method thereof.

[0057] The adsorption material and the preparation method thereof specifically comprise the following steps:

[0058] S1. Add 1.8 g of zinc acetate dihydrate (Zn(AC)2·2H2O) to 60 ml of anhydrous ethanol solution, heat to 60°C and stir for 25 min. Meanwhile, dissolve 0.6 g of potassium hydroxide (KOH) in 30 ml of anhydrous ethanol, then add the KOH solution to the Zn(AC)2·2H2O solution, stir at 50°C for 15 min, then add 240 ml of n-hexane to obtain a precipitate, centrifuge, wash and dry it to obtain a white powder. The drying temperature is 60°C and the drying time is 15 h.

[0059] S2. Add 0.2 g of the powder dried in step S1 to a mixed solution of 30 ml of benzyl alcohol and 1 g of polyethylene glycol, stir at 60° C. for 3 h, then pour it into a polytetrafluoroethylene liner, seal the reactor, heat it to 150° C. in an oven, and naturally cool it to room temperature. Centrifuge and wash it to obtain a material with a stable fluorescent effect.

[0060] S3, 200 mg of imidacloprid standard was placed in a flask, 80 ml of acetonitrile, 10 ml of deionized water and 0.2 ml of methacrylic acid were added and stirred for 4 hours, and then 0.3 g of the material with stable fluorescence effect in step S2 was added thereto. Then 20 mmol of trimethylolpropane trimethacrylate and 40 mg of 2,2-azobisisobutyronitrile were added in sequence and stirred for 15 hours, and then washed repeatedly with acetonitrile by centrifugation until no neonicotinoid pesticide standard was detected, and a fluorescent material for detecting imidacloprid was obtained.

[0061] Detection method:

[0062] Take 40 mg of fluorescent material in a centrifuge tube, add 5 ml of methanol, vortex to remove the supernatant, then add 15 ml of urine to be tested, shake for 3 minutes, and then centrifuge to obtain a white substrate, which is then dispersed in 15 ml of anhydrous ethanol, centrifuged again, and then dispersed in a mixed solution of 4 ml of isopropanol and 0.2 g of polyvinylpyrrolidone K-30, detect the fluorescence spectrum, and analyze the content of neonicotinoid pesticides.

[0063] This embodiment synthesized molecular imprinting template-wrapped ZnO microspheres, the fluorescent material absorbed 375nm ultraviolet light and emitted 596nm visible light, there were sparse hairy structures on the surface of the ZnO microspheres, the size of the ZnO microspheres was 1200nm, and the ZnO microspheres were composed of small particles of 7.8nm.

[0064] Comparative Example 1

[0065] A fluorescent material is provided, and a preparation method of the fluorescent material is the same as step S1 in embodiment 1.

[0066] Comparative Examples 2 to 4

[0067] The fluorescent materials for detecting neonicotinoid pesticides in Examples 1, 7 and 8 are respectively the results of directly testing the fluorescence spectra thereof without adding urine to be detected.

[0068] Figure 2 (a) is a transmission electron microscope photograph of the synthetic precipitate in Example 1, Figure 2(b) is a Gaussian fitting curve for statistical size. It can be seen that the size of the initially synthesized ZnO nanoparticles is relatively small. Through statistical calculation, the size distribution of the ZnO nanoparticles is 4.5-7.5 nm, and the average size is 5.9 nm.

[0069] Figure 3 is a transmission electron microscope photograph of the ZnO microspheres prepared in Example 2, Figure 3 (b) is a high-resolution transmission electron microscope photo. It can be seen that there are sparse hairy structures on the surface of the ZnO microspheres, and the ZnO microspheres are composed of smaller particles. The small ZnO nanoparticles ensure their luminescence performance, and the microspheres have a stable structure that ensures that their luminescence intensity is not easily changed over time.

[0070] Figure 4 The fluorescence emission spectrum and excitation spectrum of the ZnO nanoparticles in Comparative Example 1 over time are shown. From the fluorescence spectrum of Comparative Example 1, it can be seen that the luminescence performance of small-sized ZnO nanoparticles is unstable and easily changes with changes in the environment. This is because the surface of small-sized ZnO nanoparticles has a high surface energy, which is easy to agglomerate with each other and crystal growth, resulting in changes in their luminescence performance.

[0071] Figure 5 The fluorescence emission spectrum and excitation spectrum of the ZnO microspheres in Comparative Example 2 are changed over time. From Comparative Example 2, it can be seen that the fluorescence emission and excitation spectra of the ZnO microspheres are not easy to change, which is due to the large size and stable structure of the microspheres.

[0072] Figure 6 (a) is the fluorescence emission spectrum of neonicotinoid pesticides adsorbed by the fluorescent materials in Examples 1 to 6 and Comparative Example 2, Figure 6 (b) is a bar graph of its emission spectrum peak. From the experimental results of Comparative Example 2 and Examples 1 to 6 of fluorescent material adsorption, it can be seen that the fluorescent material without adsorbed neonicotinoid pesticides has the strongest light emission. The more neonicotinoid pesticides adsorbed, the lower the emission light of the emission spectrum. And from the bar graph, it can be seen that there is a certain trend in its reduction. This shows that the content of neonicotinoid pesticides can be judged based on the intensity of the emission light of the fluorescence spectrum. This is because the neonicotinoid pesticides adsorbed by the fluorescent material will affect its absorption of excitation light and emission of emission light, thereby affecting the intensity of its emission light.

[0073] Those skilled in the art should understand that the above are only some specific embodiments of the present invention, rather than all embodiments. It should be noted that for those of ordinary skill in the art, many modifications and improvements can be made, and all modifications or improvements that do not exceed the scope of protection of the present invention should be regarded as the scope of protection of the present invention.

Claims

1. A fluorescent material for detecting neonicotinoid pesticides, characterized in that: The invention comprises ZnO microspheres and molecular imprinting templates. The surface of the ZnO microspheres has sparse hairy structures. The size of the ZnO microspheres is 800-1200nm, and the ZnO microspheres are composed of small particles of 4.2-7.8nm. The molecular imprinting templates wrap the ZnO microspheres. The fluorescent material absorbs 375nm ultraviolet light and emits 596nm visible light.

2. The fluorescent material for detecting neonicotinoid pesticides according to claim 1, characterized in that: The molecular imprinting template is based on a neonicotinoid pesticide standard, molded with trimethylolpropane trimethacrylate and 2,2-azobisisobutyronitrile, and then repeatedly washed with acetonitrile by centrifugation to obtain an adsorption material capable of adsorbing specified neonicotinoid pesticides.

3. A method for preparing a fluorescent material for detecting neonicotinoid pesticides according to claims 1 and 2, characterized in that: The following steps are involved: S1. Add 0.8-2.4 g of zinc acetate dihydrate (Zn(AC)2·2H2O) to 40-80 ml of anhydrous ethanol solution, heat to 60-80° C. and stir for 20-30 min. Meanwhile, dissolve 0.3-0.9 g of potassium hydroxide (KOH) in 20-40 ml of anhydrous ethanol, then add the KOH solution to the Zn(AC)2·2H2O solution, stir at 30-60° C. for 10 min, then add 180-360 ml of n-hexane to obtain a precipitate, centrifuge, wash, and dry it to obtain a white powder. S2. Add 0.1-0.3 g of the powder dried in step S1 to a mixed solution of 20-40 ml of benzyl alcohol and 0.5-2 g of polyethylene glycol, and stir at 60-80° C. for 3-5 hours. Then pour it into a polytetrafluoroethylene liner, seal the reaction kettle, heat it in an oven to 120-200° C., and then naturally cool it to room temperature. Then, centrifuge and wash it to obtain a material with a stable fluorescent effect. S3, place 100-300 mg of neonicotinoid pesticide standard in a flask, add 30-100 ml of acetonitrile, 4-12 ml of deionized water and 0.1-0.5 ml of methacrylic acid and stir for 3-5 hours, then add 0.1-0.6 g of the material with stable fluorescence effect in step S2. Then add 8-30 mmol of trimethylolpropane trimethacrylate and 20-60 mg of 2,2-azobisisobutyronitrile in sequence and stir for 16-20 hours, then wash repeatedly with acetonitrile by centrifugation until the neonicotinoid pesticide standard cannot be detected, and obtain the fluorescent material for detecting neonicotinoid pesticides.

4. The method for preparing a fluorescent material for detecting neonicotinoid pesticides according to claim 3, characterized in that: The drying condition in step S1 is 50-80° C. and the drying time is 12-18 hours.

5. The method for preparing a fluorescent material for detecting neonicotinoid pesticides according to claim 3, characterized in that: In step S3, the neonicotinoid pesticide standard product is imidacloprid.

6. A detection method for detecting neonicotinoid pesticides according to claims 1 and 2, characterized in that: The following steps are involved: Put the fluorescent material in a centrifuge tube, add methanol and vortex to remove the supernatant, then add the urine to be tested, shake for 2 to 3 minutes, and then centrifuge to obtain a white substrate, which is then dispersed in anhydrous ethanol, centrifuged again, and then dispersed in a mixed solution of isopropanol and polyvinyl pyrrolidone K-30, detect the fluorescence spectrum, and analyze the content of neonicotinoid pesticides.

7. The method for detecting neonicotinoid pesticides according to claim 6, characterized in that: The added amounts of the fluorescent material, methanol, urine to be tested, anhydrous ethanol, isopropanol and polyvinylpyrrolidone K-30 are 30-60 mg, 3-6 ml, 10-20 ml, 15-20 ml, 3-5 ml and 0.1-0.3 g respectively.

Images